1. Field of the Invention
The present invention pertains to signs such as temporary warning signs which may be collapsed for storage in a reduced space and readily erected upon demand.
2. Description of Related Art
Warning signs are provided for a variety of purposes. Among the more demanding applications, is the use of roadside warning signs to advise motorists and pedestrians of activity being conducted at a work site. This type of signage allows those present in the vicinity to be alerted before entering the center of the work area so that appropriate action may be taken. Such signs are used, for example, by utility companies and others who maintain dedicated service in residential areas, and who may be required to perform repairs and other work activities in close proximity to pedestrian or vehicular traffic. With the presence of appropriate warning signs, pedestrian traffic is advised that objects unusual for the area may impede their progress of movement, that objects may be temporarily suspended above them or that other conditions may warrant careful scrutiny while traversing a work area. Vehicular traffic approaching a work site can, with sufficient amounts of properly located signage, be advised that traffic is being diverted or that traffic may be required to stop or slow down to avoid contact with workmen or construction vehicles, for example.
For long term projects, appropriate signage can be ordered ahead of time and installed in a permanent or semi-permanent fashion, after a detailed study of the particular work area. However, utility companies, highway departments, providers of emergency services and others may be required to establish a work area, virtually on a moment""s notice. For example, management of a traffic accident scene may require appropriate signage to be erected in a traffic lane or at a roadside or other location, on an emergency basis.
Bearing in mind that such signage must be large enough to present adequate notice to motorists and others passing by an area, consideration of the sign""s size and weight must be taken into account when outfitting a work team. It is impractical in such instances to require work personnel to employ bulky, massive signage. Accordingly, lightweight so-called xe2x80x9croll-upxe2x80x9d signs are becoming increasingly popular with a variety of different users. With lightweight collapsible signs, utility construction or repair crews can carry a number of such signs as standard equipment which is maintained in the vehicles at all times.
One example of a commercially popular collapsible sign panel is the Model No. 3000XP sign panels offered for sale by the assignee of the present invention. The collapsible sign panel employs aluminum tubing arms and a central mounting system which allows the panel to fold together before rolling into a compact bundle that is more easily stored in tight places. The sign panels are made of flexible retro-reflective material which is folded as the arms are pivoted about the hub. The flexible panel is then wound about the collapsed arms to form a compact, cylindrical package of minimal size. Sign panels which are as large as three feet and four feet on a side are typical.
U.S. Pat. No. 4,694,601 assigned to the assignee of the present invention shows a portable collapsible sign which has also enjoyed commercial success. Various sign stand assemblies employ spring loading features to balance wind deflection forces. Ground-engaging legs for supporting the erected sign panel may be permanently attached to the sign panel or may be provided in a separate assembly which is typically mated to the erected sign panel with a slip fit or other type of engagement.
With easily portable sign panel assemblies of the above-described type, the use of signage at temporary workplace locations is becoming more consistent due to the practicality and ease of use afforded worksite personnel. However, further improvements are still being sought. For example, continued improvements and simplifications of the sign assembly mechanisms are continually being sought.
The Transportation Research Board (TRB) is a unit of the National Research Council, a private, nonprofit institution that is the principal operating agency of the National Academy of Sciences (established by Congress in 1863) and the National Academy of Engineering. The mission of the Transportation Research Board is to promote innovation and progress in transportation by stimulating and conducting research, facilitating the dissemination of information, and encouraging the implementation of research results.
The Transportation Research Board fulfills its mission through the work of its standing technical committees and task forces addressing all modes and aspects of transportation. Duties include conducting special studies on transportation policy issues at the request of the U.S. Congress and government agencies as well as operation of an on-line computerized file of transportation research information and the hosting of an annual meeting that attracts a large number of transportation professionals from throughout the United States and abroad.
The Transportation Research Board administers two cooperative research programs: The first program, the National Cooperative Highway Research Program (NCHRP) is sponsored by the member departments of the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration, the National Cooperative Highway Research Program and the Transit Cooperative Research Program. The National Cooperative Highway Research Program was created in 1962 as a means of conducting research in acute problem areas that affect highway planning, design, construction, operation, and maintenance nationwide.
The second program, named the Transit Cooperative Research Program (TCRP), is sponsored by the Federal Transit Administration and is carried out under a three-way agreement among the National Academy of Sciences (acting through the Transportation Research Board), the Transit Development Corporation, Inc. (a nonprofit educational and research organization established by the American Public Transportation Association) and the Federal Transit Administration. The Transit Cooperative Research Program serves as one of the principal means by which the transit industry can develop innovative near-term solutions to meet demands placed on public transit systems.
Currently, developers of roadside safety hardware are guided by testing requirements using a range of criteria defined by Report 350 of the National Cooperative Highway Research Program (NCHRP), entitled xe2x80x9cRecommended Procedures for the Safety Performance Evaluation of Highway Features.xe2x80x9d NCHRP Report 350, incorporated significant changes and additions to procedures for safety performance evaluation, including criteria for multiple performance levels, guidelines for testing features not previously addressed, translation to metric units, and updates reflecting the changing character of the highway network and the vehicles using it. Concerns have been raised that some existing hardware, which is observed to be performing adequately in the field, may have difficulty passing new tests and evaluation criteria. Further study and testing has been called for in an attempt to improve roadside safety by establishing crashworthiness criteria that reflects changes to the vehicle fleet and safety hardware technology.
In its Jul. 25, 1997 guidance memo, xe2x80x9cIdentifying Acceptable Highway Safety Features,xe2x80x9d the Federal Highway Administration established four categories of work zone devices. It also set deadlines requiring devices within each category to be crashworthy under the National Cooperative Highway Research Program Report 350 criteria.
Work crews, such as those servicing and installing utility equipment, are required to operate at or near operational highways and other roadways. Temporary sign assemblies are typically carried by the work crew and are installed at a roadside location so as to give oncoming motorists time to react to the unexpected appearance of equipment and personnel, at or near the highway roadside. At times, a work crews operations will be very brief. Nonetheless, it is important that roadside warnings in accordance with recent safety regulations, be set up in advance of work commencement. To be commercially successful, a temporary sign assembly must be capable of quick and easy deployment.
It is an object of the present invention to develop temporary sign assemblies that are good candidates for offering a satisfactory performance when tested under various safety programs.
It is another object of the present invention to provide sign panel assemblies having an improved ease of operation, with low mass, conformable, dynamically reconfigurable members.
A further object of the present invention is to make it possible for police vehicles, survey teams and others which typically employ automobile and other similar sized vehicles to carry several signs in the trunks of their vehicles. These and other objects of the present invention are provided in a support arrangement, a base, a force accumulator tube of hollow predetermined cross-section outwardly extends from the base and has a free edge spaced from the base. A support tube of hollow complementary cross-section telescopically engages in a close-sized fit with force accumulator tube so as to have a predetermined portion which extends beyond the free edge of force accumulator tube. An insertion limiter cooperates with force accumulator tube and support tube to limit telescopic engagement of support tube and force accumulator tube, aligns with predetermined portion with the free edge of force accumulator tube, and predetermined portion of support tube includes a plurality of weakening members aligned with the free edge of force accumulator tube. A lateral force applied to sign support arrangement is accumulated at free edge of force accumulator tube and is developed at predetermined portion of support tube.
Other objects are attained in a support arrangement, a base plate, a force accumulator tube of hollow predetermined cross-section depends from base plate, force accumulator having a free edge spaced from the base plate, support tube of hollow complementary cross-section, has a lower edge. A support plate at the bottom of support tube, support plate spaced from base plate to form a gap therewith. A tension arrangement extends between base plate and support plate, urging said base plate and support plate away from one another, a connecting tube having opposed ends telescopically engaged in a close-sized fit with force accumulator tube and support tube, and spanning the gap between support plate and base plate first and second insertion limiters cooperating with force accumulator tube, connecting tube and support tube to limit telescopic engagement of connecting tube and force accumulator tube limiting telescopic engagement of support tube and force accumulator tube, aligning a predetermined portion of connecting tube with a force accumulator tube free edge, and predetermined portion of connecting tube including a plurality of weakening members aligned with the free edge of force accumulator tube. A lateral force applied to sign support arrangement is accumulated at the free edge of force accumulator tube and is developed at predetermined portion of connecting tube.